The present invention relates to a pump for feeding liquid substances, and more particularly to a pump having a structure suitable to feeding semi-liquid substances having high viscosity, in which feeding is achieved consecutively rather than intermittently.
In general, the conventional two-stroke type cylinder pump acts using inhalation and compression. This type of pump has the disadvantage in that the operations of inhalation and compression are conducted intermittently. A centrifugal pump feeds by using the centrifugal force of an impeller and has an advantage of continuous feeding. This pump is very sensitive to the viscosity of the substance being fed and thus has the disadvantage that substances having some viscosities cannot become the object of feeding.
In order to feed viscous substances, a pump having a structure similar to a vane pump is mainly used. This pump, being driven according to the viscosity, especially should be controlled by the substance being fed by means of continuous use. For this reason, it has the disadvantage of rising maintenance fees and frequent troubles. It also has the drawback of low volume ratio.
Further, a pump using a diaphragm was conceived in recent years. This pump settled some problems of the general pump. However, in pumps having such structure, the diaphragm consisting of soft rubber is restricted to the pressure limit enabling the feeding. For this reason, it has a problem in which the diaphragm is frequently torn when feeding a high viscosity substance.
To solve the conventional problems described above, the present invention was conceived. A pump according to the present invention has a structure which does not require any separate controller for controlling the driving of the pump, and by which continuous feeding can be performed without interruption, as the pump is automatically operated without regard to the viscosity of the substance being fed.
There is another invention related to the present invention, which was filed in Korea on Aug. 8, 1996 by the present applicant (Utility Model Application No. 23928).
The present invention was conceived to solve the conventional problems described above. An object of the present invention is to provide a pump having a structure that enables consecutive feeding. Inhalation and discharge of the substance being fed are achieved by means of interlocking pump piston operation. The piston rod of the air cylinder is reciprocated with the power of compressed air, and the reciprocating stroke operation of the pump is automatically adjusted by the flexible match of compressed air in accordance with the viscosity of the substance being fed.